I. Field of the Invention
The present invention relates generally to the fields of oncology and virology. More particularly, it concerns poxviruses, specifically including oncolytic vaccinia viruses suitable for the treatment of cancer and their use in combination with anti-angiogenic agents.
II. Background
Normal tissue homeostasis is a highly regulated process of cell proliferation and cell death. An imbalance of either cell proliferation or cell death can develop into a cancerous state (Solyanik et al., 1995; Stokke et al., 1997; Mumby and Walter, 1991; Natoli et al., 1998; Magi-Galluzzi et al., 1998). For example, cervical, kidney, lung, pancreatic, colorectal, and brain cancer are just a few examples of the many cancers that can result (Erlandsson, 1998; Kolmel, 1998; Mangray and King, 1998; Mougin et al., 1998). In fact, the occurrence of cancer is so high that over 500,000 deaths per year are attributed to cancer in the United States alone.
Currently, there are few effective options for the treatment of many common cancer types. The course of treatment for a given individual depends on the diagnosis, the stage to which the disease has developed and factors such as age, sex, and general health of the patient. The most conventional options of cancer treatment are surgery, radiation therapy and chemotherapy. Surgery plays a central role in the diagnosis and treatment of cancer. Typically, a surgical approach is required for biopsy and to remove cancerous growth. However, if the cancer has metastasized and is widespread, surgery is unlikely to result in a cure and an alternate approach must be taken.
Replication-selective oncolytic viruses hold promise for the treatment of cancer (Kirn et al., 2001). These viruses can cause tumor cell death through direct replication-dependent and/or viral gene expression-dependent oncolytic effects (Kirn et al., 2001). In addition, viruses are able to enhance the induction of cell-mediated antitumoral immunity within the host (Todo et al., 2001; Sinkovics et al., 2000). These viruses also can be engineered to expressed therapeutic transgenes within the tumor to enhance antitumoral efficacy (Hermiston, 2000). However, major limitations exist to this therapeutic approach as well.
Therefore, more additional therapies for the treatment of cancer are needed. The use of oncolytic viruses presents a potential area for development.